The present invention relates to a device for handling ink in an ink jet recording apparatus in which a recording head is moved across the width of recording paper and jets ink drops onto the recording paper in response to print data for forming an image.
An on-demand ink jet recording apparatus which jets ink pressurized at a pressure generation chamber through a nozzle onto recording paper as ink droplets for recording print data exhibits substantial problems. Among these problems are a rise in viscosity caused by evaporation of an ink solvent from nozzle openings and print failure caused by drying of ink, adhesion of dust, and mixing of air bubbles. Thus, an ink jet recording apparatus of this type is generally provided with a capping device for sealing the nozzle openings when no printing is being performed and a device for cleaning around the nozzle openings as required.
A proposed capping device includes a slider which is moved by a carriage to a home position along a slant guide face disposed on a frame to the nozzle opening face side of a head, and a cap disposed on the surface of the slider is pressed against the recording head for sealing the nozzle openings, for example. Such an arrangement is disclosed in Japanese Patent Laid-Open No. Hei 1-125239.
For such an ink jet recording apparatus, an ink tank is furnished in cartridge form which provides a convenient ink supply. When the ink has been consumed, the ink cartridge is replaced with a new one. One such ink cartridge is disclosed in Japanese Patent Laid-Open No. Hei 2-187364, in which a porous substance forming an ink absorber is housed in the ink cartridge. Annular packing material is disposed on the tip of an ink outlet for sealing. Since ink can be easily supplied by simply changing ink cartridges, the ink cartridge is very useful in preventing pollution caused by ink leakage, etc., at the ink supply. On the other hand, the ink cartridge has a disadvantage in that air bubbles are prone to enter the ink cartridge by piston action between an ink supply needle on the main unit side and the ink outlet of the ink cartridge when the ink supply needle is inserted.
Further, because of the ease of changing the ink supply, the ink cartridge is removed and then remounted even when ink remains in the cartridge. As a result, air bubbles enter the ink cartridge by the piston action and cause print failure to occur.